Du kan købe hvad som helst i kiosken, hvis du har penge med.

Because kan is a modal verb, and modal verbs are followed by another verb in the infinitive.

So the structure is:

• Du = subject
• kan = finite verb
• købe = infinitive

In Danish main clauses, the finite verb normally comes in second position, so kan comes early in the sentence, while købe stays later.

After modal verbs such as kan, vil, skal, må, bør, Danish normally uses a bare infinitive, without at.

So:

• du kan købe
• not du kan at købe

This is similar to English can buy, not can to buy.

It can suggest possibility or ability, depending on context.

In this sentence, kan most naturally means something like:

• it is possible for you to buy things there
• you are able to buy things there, provided you have money with you

It does not mainly sound like formal permission here.

Hvad som helst is a fixed expression meaning anything at all or whatever.

It is built from:

• hvad = what
• som helst = an intensifying part that gives the idea of no matter which / no matter what

So hvad som helst means that there is no restriction on the thing.

Similar expressions are:

• hvem som helst = anyone at all
• hvor som helst = anywhere at all
• hvornår som helst = anytime at all

Sometimes, but the nuance is different.

• alt means everything
• hvad som helst means anything at all

So hvad som helst stresses unrestricted choice. It is usually the better choice if you want the sense of no matter what thing.

Because kiosken is the definite form, meaning the kiosk.

So:

• i kiosken = in/at the kiosk
• i en kiosk = in/at a kiosk

Using kiosken suggests that the kiosk is specific, known, or understood from context.

Also, i is the normal preposition here.

Because penge is being used in a general sense: money.

In Danish, when talking about money in general, you usually just say penge, without an article.

So:

• har penge med = have money with you

You are not talking about a specific set of coins or notes, just whether you have money available.

Also, penge behaves like a plural-only noun in modern Danish. For one unit, Danish normally uses words like:

• en krone
• en mønt
• en seddel

Because have ... med is a common Danish expression meaning to have something with you or to bring something along.

The pattern is often:

• have + object + med

So:

• du har penge med
• jeg har min telefon med
• har du pas med?

This final med is very natural in Danish and should be learned as part of the expression.

No. The normal order is:

• har penge med

The object usually comes before the final particle med.

So the correct structure is:

• verb + object + med

not

• verb + med
  • object

Because hvis introduces a subordinate clause.

In Danish main clauses, the finite verb usually comes in second position. But in subordinate clauses, the word order is more straightforward:

• hvis + subject + verb

So:

• hvis du har penge med

That is normal subordinate-clause order.

If this were a main clause question, you could say:

• Har du penge med?

But after hvis, you do not use that question-like inversion.

Hvis means if and introduces a condition.

Når usually means when, often for something expected, repeated, or certain to happen.

In this sentence, having money is a condition, so hvis is the right choice.

Compare:

• Hvis du har penge med, kan du købe noget = if you have money with you, you can buy something
• Når du har penge med, køber du tit noget = when you have money with you, you often buy something

In modern Danish, du is the normal word for you in almost all situations.

A formal form, De, does exist, but it is now rare and sounds very formal, distant, or old-fashioned in many contexts.

So for most learners, du is the correct and natural choice.